21103100 has 36 divisors (see below), whose sum is σ = 46017888. Its totient is φ = 8400000.

The previous prime is 21103087. The next prime is 21103109. The reversal of 21103100 is 130112.

It is a super-2 number, since 2×21103100² = 890681659220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27725 + ... + 28475.

Almost surely, 2^21103100 is an apocalyptic number.

21103100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21103100 is an abundant number, since it is smaller than the sum of its proper divisors (24914788).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21103100 is a wasteful number, since it uses less digits than its factorization.

21103100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1046 (or 1039 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 8.

The square root of 21103100 is about 4593.8110540160. The cubic root of 21103100 is about 276.3431808944.

Adding to 21103100 its reverse (130112), we get a palindrome (21233212).

The spelling of 21103100 in words is "twenty-one million, one hundred three thousand, one hundred".